Voting systems like Reddit's would be more useful if they weren't so easily gamed by bots and brigades. A costly voting system like SN's could go some way towards addressing this, depending on how it gets implemented.

r/cryptocurrency is a good case study in what not to do. When the mods introduced a rewards token, the forum quickly became overran by attempts to farm it. Memes, sloppily written how-to guides, boring "unpopular opinion" posts, etc. It seemed to make the sub much worse (and it was something of a cesspool to begin with).